Published: May 19, 2011

Lalo de Almeida for The New York Times

Andreia Soares played with a child at her employer's home. The training she has received has helped her command higher pay.

With the money she saved, she bought a two-bedroom apartment with granite kitchen countertops and a small veranda, a house for her mother, a plot of land for her brother and a Louis Vuitton purse from Paris that she proudly pulls from a closet.

Later this year, with her monthly salary of $3,100, which she earns caring for a 10-month-old girl in an upscale neighborhood, she plans to buy a $39,000 car — in cash.

“I have always had this dream of buying a house and a car,” said Ms. Soares, 39. “Today that dream is closer than ever for nannies.”

While she has done better than many of her counterparts, Ms. Soares is part of a nanny revolution that is shattering the colonial stereotype of inexpensive but dedicated domestic help in Latin America.

As their expectations for a better quality of life rise, nannies are increasingly seeking to work for the very wealthy and becoming less affordable for many middle-class families. The shift is causing ripples of class tension, posing a nettlesome problem in a society in which more women are entering the work force without the sort of elaborate system of day care that exists in some industrialized nations.

Fading fast are the days when white-frocked nannies worked for a menial salary, with only two days off every 15 days. Better-qualified nannies are refusing to work weekends and are demanding salaries that are two to four times what they were paid just five years ago. A growing number are refusing to sleep over or are leaving the field, choosing jobs that allow more time for a private life, according to parents, nannies and directors of nanny placement agencies.

The income of domestic employees in Brazil, including nannies and maids, rose 34 percent from 2003 to 2009 — more than twice the average increase for all of Brazil’s active workers — said Marcelo Neri, an economist at the Getúlio Vargas Foundation. At the same time, he said, the working hours of domestic employees fell by 5 percent to 36.2 hours a week.

“Today, what I need from a nanny job is different than before,” said Ieda Barreto, 32. Seven years ago, she was making about $400 a month and had only 24 hours off every Thursday, making it tough to hold onto a boyfriend. Today she expects to make almost $1,900 working Monday to Friday, and she charges an additional $250 to work weekends.

“I am looking for quality of life,” Ms. Barreto said. “I value myself much more than I did before.”

The rising expectations reflect the growth of Brazil’s middle class, which rose to nearly 55 percent of the population in 2010 from 37 percent in 2003, Dr. Neri said.

Today, “Brazil is becoming like the United States,” where hourly paid housekeepers are more common than sleep-over nannies, said Jacqueline Szwarc, a psychologist who was picking up her children outside a private school in São Paulo. “The salaries have gotten very high, and the search for domestic help has become very difficult.”

The supply of nannies has thinned as some have sought other work in the expanding job market, driving up salaries for those who stay in the field, economists, nannies and nanny agency directors said. Many remaining nannies are taking courses to become better qualified and to help them find work in wealthier homes, where they can charge much more.

While some mothers embrace the changes as good for Brazil’s development, many are up in arms. Once isolated, nannies now trade information about the market and working conditions through e-mail, blogs and social networks.

“It’s a mafia,” said Ms. Szwarc, 44, adding that she has been lucky to hold onto the same nanny for 10 years.

Six years ago, Evanice dos Santos, a former nanny turned blogger, had no Internet access and caught up with fellow nannies at a São Paulo athletic club where her employers were members. Now married, she has dedicated herself to helping nanny friends online “find a better path” toward more money and better hours.

Some well-paid nannies in São Paulo are employing nannies of their own. Ms. Soares said nanny friends earning more than $4,300 a month were paying less-qualified nannies a little over $900 a month to baby-sit for their own children.

Like a growing number of parents, Rafaella Toledo brought in her nanny from Paraguay, and parents said nannies from Peru were also arriving in São Paulo. “The situation is terrible,” Ms. Toledo said. “Now that I am pregnant I am going to look for someone that isn’t a nanny, because nannies think they are on another level now.”

Michelle Tchernobilsky, 29, has changed nannies about 10 times in the past year, searching for someone affordable yet qualified enough to care for her 10-month-old son. Cutting the nanny from her budget is not an option for Ms. Tchernobilsky, a public relations manager, but neither is paying a salary that she considers exorbitant. “We are hostages,” she said.

Marilia Toledo, the owner of the Masa nanny agency, said the market in São Paulo, South America’s largest city, had become a “war” between demanding nannies and parents trying to hold back nanny inflation. “Things are changing too quickly and abruptly,” said Ms. Toledo, who has owned the agency for 20 years. “No one was prepared for this.”

Among the top requests she receives, she says, is for a nanny who has never worked in São Paulo because they are “more humble.”

Ms. Toledo and some economists are skeptical about how long the revolution can last. Dr. Neri said Brazilians still had low education levels: an average of seven years of study for adults older than 25. Rodrigo Constantino, an economist at Graphus Capital, said a lack of investment in education in Brazil would prevent many domestic workers from finding other, better-paying work, and incessant salary demands could stoke inflation.

“Brazil is riding this wave, and each class is moving up the ladder,” Mr. Constantino said. “The problem I see is how this is going to be sustainable.”

Still, nannies like Ms. Soares are investing in themselves. It began nine years ago when she took a nursing course. She followed up two years later with specialized nanny courses at a so-called baby-sitting center. Next year she plans to take English lessons.

“People in our field are starting to get more qualifications and they are looking for families with more money to pay them,” Ms. Soares said. “Because of that, a lot of women are losing their nannies.”

After a two-year stint working as a nanny in New York, she found her way last year to the home of Fernanda Parodi, a lawyer married to a chief executive in São Paulo. Ms. Parodi says she has no complaints about Ms. Soares’s salary, though she is counseling her to buy a cheaper car.

“I don’t ever want her to leave,” said Ms. Parodi, 38, who is considering promoting her to personal assistant.

Where some mothers see a debilitating revolution, she sees social progress. “If Brazil wants to move beyond a third-world country, then it needs to allow everyone to participate in the growth,” Ms. Parodi said. “It’s the price you pay for progress.”